원문정보
초록
영어
Saccharomyces cerevisiae is effective for industrial scale production of bioethanol, but it cannot utilize xylose present in high amounts in lignocellulosic biomass. The effects of two different sugars on the expression levels and patterns of xylose reductase (xyl1), xylitol dehydrogenase (xyl2) and xylulokinase (xyl3) genes were analyzed using Pichia stipitis. A significant
increase in mRNA levels of xyl1 was observed in culture conditions using xylose as a sole carbon source, but expressions of the three genes were not influenced by culture media with glucose. It also was found that the expression level of xyl1 increased as a function of the xylose concentration used in this study. Therefore, we constructed new recombinant S. cerevisiae harboring xyl1, xyl2 and xyl3 gene isolated from P. stipitis. Proteomic and fermentaion analyses revealed that three foreign genes were successfully expressed in S. cerevisiae grown on xylose or on glucose/xylose mixtures and ethanol production also was observed in S. cerevisiae grown on xylose. In addition, the expression level of xyl1, xyl2 and xyl3 proteins in cells grown on a xylose and glucose/xylose mixture was increased. These results suggest that regulation of
xylose utilization in recombinant S. cerevisiae is successfully performed as seen in S. cerevisiae, which originally cannot utilize xylose.